1. Field of the Invention
The present invention relates in general to plastic material shaping and dispensing, and more particularly to an apparatus and method for dividing and delivering dough or similar plastic material in discrete portions.
2. Description of the Prior Art
Manufacture of small articles made from dough such as doughnuts, dumplings, and small cakes, requires accurate, repeatable dispensing of discrete portions of dough.
Dumplings, for example, usually no more than about one inch long and one half inch in diameter, are manufactured by separating out and dropping individual portions of dough into boiling water. The individual portions must be of uniform size and cleanly separated one from the other's end, and must fall separately so that they do not stick together. The boiling water causes their outer surfaces to congeal, preventing sticking while they cook. The uniform shape and size, piece to piece, assures equal cooking time requirement for each.
The simplest way to obtain separate portions of dough is to spread it out evenly on a board, trim it into a strip that is as wide as the desired length of the portion, and progressively cut the strip transversely into portion widths, scraping each portion off in turn into the boiling water. This is the most common home-method. Depending upon the skill of the operator, the portions can be quite uniform, though the method is slow.
A simple apparatus familiar to Old World kitchens is the combination of a shallow pan with perforated bottom, typically with three-eights inch diameter holes, and a large spoon. The pan is held about eight inches above the boiling water while dough, held in the pan, is pressed down through the holes by the spoon. Portion sizes vary, but the method is a little faster.
Simultaneous delivery of portions is obtained in home kitchens by sliding a small dough-filled hopper over a perforated sieve. The bottom edges of the hopper's leading and trailing walls are made to closely fit the sieve surface so that dough delivery is halted as the walls pass over the holes. Dough must be forced down in the hopper by palm pressure, as with a piston, in order to force it through the holes. Cut-off of and the amount of dough varies from portion to portion.
The rate of portion delivery is improved by use of the home apparatus shown in FIG. 1. Referring to the figure, and numbering of parts therein, bowl 20 is partially filled with dough. As shaft 22 is rotated by handle 24, while the apparatus is kept from turning by fixed handle 26, dough is forced down through holes 28 in perforated bottom 30 by the angled surfaces of blade 32. The length of the portions vary as they are delivered from near the center to the outer diameter of the perforated bottom. Portions exiting near the center of the bottom tend to congeal together due to the relatively slower motion of the blades over that area.
Another kitchen machine is shown in FIG. 2. As cylinder 34 is rotated within housing 36, dough 38 is drawn around into a ribbon between the cylinder and the housing wall. The dough is separated from the cylinder by scraper edge 40, and breaks apart as its weight accumulates at the scraper edge slot 42. The diameter of the pieces which fall into the boiling water container 44, depends upon the consistency of the dough. Their length is limited to the width of the cylinder and length of the scraper edge and slot.
U.S. Pat. No. 2,230,094 awarded to George E. Tubbs, Jan. 28, 1941, teaches a circular housing having an opening at the top for a dough hopper and an opening at the bottom for ejecting dough through a tube.
At the bottom of the tube there is located a reciprocating tubular cut-off and sealing device. Within the hollow housing there is located a concave piston face which reciprocates in an arc across the opening to the dough hopper. A partition plate seals off a portion of the housing so that the concave face draws a partial vacuum as it moves away from the opening to the tube, toward and then across the opening to the dough hopper, thereby drawing dough into the housing.
When the concave face reciprocates back across the opening to the hopper, on its way toward the opening to the tube, a rear portion of the face seals the opening to the hopper while the advancing concave face forces the dough into the tube. The tube cutting device opens to release a portion of dough and then seals, cutting the dough off in the form of a ring, whereupon it is received on a conveyer for processing.
Changes can be made in portion size by changing the stroke arc of the piston, or the stroke or timing of the tubular cutting device. The machine is designed for producing sequential shaped portions, one at a time.
Another machine for providing measured portions of dough, one at a time, is described in U.S. Pat. No. 1,777,178, awarded to Ezio Pensotti on Sept. 30, 1930. In Pensotti, a drum having recesses about its periphery, rotates within a housing that is open to a dough hopper. Each recess includes a closely fitting rotating flapper which scoops the dough out of the recess as the recess passes a cut-off knife edge that extends from the housing. A portion of the dough is forced back into its source-mass before the knife edge, while the remainder of the recess dough is separated from the drum by the knife as the trailing edge of the recess passes the knife.
The dough's tendency to stick to cut-off surfaces is considerably overcome by the minimal cross sectional area of the knife edge opposed to the surface of the flapper and drum.
U.S. Pat. No. 1,857,927, awarded to Jack Mason, May 10, 1932, discloses a housing having a dough-feeding hopper which has at its lower end a feed roller which, by its surface that can be roughened, draws the dough into the housing.
Below the feed roller, there is a drum containing a piston in a through-channel running through and perpendicular to the drum's central axis. The piston has opposed cam shaped faces which form 180 degrees apart pockets within the channel opening and the drum outer diameter.
A roller and a scraper are located at the outer surface of the drum. As the drum rotates, the roller on one side cams against the piston face, driving the piston toward the other side of the drum. Excess dough, collected in the pocket, is cut off by an edge comprising a portion of the housing inner diameter.
Whereby the remainder of the material in the pocket that is formed by the piston head and its recess within the drum is released onto a conveyor for further processing.
The scraper blade serves to clean the cam surface. For each portion of dough delivered by the machine, the drum makes one half revolution, while the feed roller generally makes about three in order to drag enough dough into the machine for a one portion charge.
U.S. Pat. No. 3,602,156 awarded to Albert Verhoeven on Aug. 31, 1971, discloses a machine to deposit cookie dough, jams, candies and the like in which the deposit cycle is followed by a suction on the undeposited material to draw the undeposited material back into the extruder for a better separation between the deposited and undeposited material.
For that purpose, Verhoeven discloses a hopper having a star-shaped cam in communication with the dough hopper. A cam-follower finger is disposed within a dough-delivering chamber which communicates with an effluent port or tube. When the cam follower finger is driven toward the effluent port by a cam lobe, it forces dough out through the port. As the cam follower finger returns to the position between cam lobes, it develops a suction on the effluent port.
The mass of the dough portion beyond the orifice of the effluent port, and synchronized movement of a receiving belt located below the effluent port orifice, preclude drawing of the dough back into the delivering chamber by way of the effluent port when the suction is developed by the camming finger as it withdraws from the region of the effluent port.
H. C. Rhodes, in U.S. Pat. No. 2,221,328, awarded Nov. 12, 1940, discloses a pneumatic dough feeder for use in charging receiving pockets in a reciprocal-plunger dough-dividing machine.
For this purpose he discloses a cam-shaped transfer roller operating within a housing and in communication with a dough hopper. A slidingly but yieldingly seated gate seals against the surface of the cam so that a substantially air tight condition is maintained between the cam face, the exit side of the housing, and its opening to a reservoir for storage of the dough under pressure.
As the cam rotates it forces the dough out through the opening so that it is delivered by way of the reservoir to the receiving pocket of the reciprocal piston dough separator. A float on the exiting pressure side of the housing, controls the amount of dough delivered to the reservoir by the cam arrangement.
The present machines for dividing and delivering dough in discrete portions are generally designed for delivering portions sequentially, although their systems can be ganged for multiple portion delivery. While their systems are adequate for manufacturing bread loaves and doughnuts, they do not lend themselves to economical or high speed delivery of predetermined portions for smaller articles of dough such as dumplings.